Sewing machine attachment



Sept. 25, 1951 N. BATES SEWING MACHINE ATTACHMENT Filed Dec. 22, 1947 llkw I i] A 1/ Mim 2 Sheets-Sheet 1 o l N IHII h 'IH M ll INVENTOR.

A Tram/Ev Sept. 25, 1951 N. BATES SEWING MACHINE ATTACHMENT 2 t e e h s S t e e h s 2 an w Filed Dec. 22, 1947 INVENTOR. L/Va 2%(10 45a zeus A TTOENEY Patented Sept. 25, 1951 SEWING MACHINE ATTACHMENT I Nathan Bates, Bartow, Fla'., assigno'r, by mes'ne' assignments,- to Swift & Company, a corpora tion of- Illinois Appl ication December 22, 1947, Serial No. 793,27?

This invention relates generally to an attachment for sewing machines and more particularly to a thread cutting attachment for sewing machines.

the closing of bags, and in many other 111* stances where articles are stitched one after another, it is the practice to continually convey the articles to a sewing machine operating at a high rate of speed. The articles are fed to the sewing machine by the operator, generally without stopping the machine during the interval betweenthe final stitching operation on one article and the initial stitching operation on the succeeding article. This results in the successive articles being connected by a chaining thread or a series of thread loops which have to be out.

Heretofore, the practice in many plants employ'ing sewing machines for closing filled bags or the like has been to have the operator cut the chaining threads with a knife, shears, or by forc ing the thread against a cutting edge mounted adjacent the sewing head of the machine. When the latter procedure is employed, the operators thumb or handis continually sore and tender, often necessitating the use of surgical dressing. Moreover, since one of the operators hands is almost constantly engaged in cutting the chaining threads, it is often necessary to have two operas tors for each bag sewing machine. I

In some plants it has been proposed to equip sewing machines with attachments which sever the chaining threads automatically after the stitching operation on the article is completed.

These attachments have not been entirely satisfactory because of their complexity or the necesslty 5f modifying the sewing machine before attaching the thread severing means;

The present invention contemplates providing a sewing machine with a thread severing attachment which automatically cooperates with a cutting edge mounted adjacent the sewing head to cut the chaining threads immediately after the article being stitched asses the sewing head.

One of the principal objects of the invention is to provide an inexpensive chaining thread cutter which is readily attached to existing sewing machines.

Another object of the invention is to provide an efficient and inexpensive attachment for sewing machines whereby the chaining thread cutting operation is made automatic.

A further object of the invention is to provide means whereby economy in the thread, time, and the labor may be elfected in the operation of cutting the chaining threads at the end of the sewing operation. v

' description.

In the drawings:

Figure l is a side elevation view of a bag closing sewing machine showing one embodiment of the present invention applied thereto during the sewing operation. 7

Figure 2 is a side elevation view of the sewing machine with the invention applied thereto just after the completion of the sewing operation.

Figure 3 is a plan View of the cutting attachment shown in Figure 2.

Figure 4 is a sectional view on lines 4-4 of Figure 3.

Figure 5 shows a view of a modified form of the support for the cutting attachment.

Figure 6 is a side elevation view of another embodiment of the sewing machine cutting attachment.

Referring more particularly to the drawings, the numeral l0 designates generally a bag sewing machine of the usual type, including a sewing head I I having a presser foot I2 with a heel section l2 carried by rods l3 yieldably pressing the upper edge of the filled bag l4 against the work support l5. The filled bag I4 is continuously conveyed from a filling mechanism along a hori-' zontal path through the sewing machine In by a continuous conveyor not shown, The work support l5 carries a cutting edge ll with which the thread cutting attachment [8 cooperates to automatically sever the chaining threads I!) connecting successively stitched bags. 1

The attachment [8 embodying one form of the present invention comprises a supporting bracket 20 secured to the sewing machine in any suitable manner such as by a plurality of screws 2| on one side of the path of the stitched articles through the machine. The supporting bracket 2!] is disposed so that the end thereof is spaced rearward-r ly of the trailing edge or heel section of the presser foot 12 and spaced oppositely from the cutting edge disposed on the other side of the path of the stitched article through the machine and which is generally, but not necessarily, mounted on the work support l5. On the forward edge of the outer end of said supporting bracketlll is 3 suitably secured a U-shaped support 22 extending slightly beyond the end of the bracket 28' and having openings 23, 23 therein to provide support for a pin 24. Although the supporting bracket and the U-shaped support 22 are herein shown as separate parts, it should be understood that these may be made as a single unitary structure. On the pin 24 is pivotally mounted an article engaging member 25 and a spring 26. The article engaging member 25 is provided with a flat surface 21 on the forward side thereof for engaging the surface of the article being stitched and has rearwardly extending lateral flanges 28, 28 which straddle the U-shaped support 22. The flat surface 21 is curved inwardly rather sharply at the leading edge 29 and only slightly at the other end. The lateral flanges 28, 28' likewise taper slightly toward each end. The pin 24 passes through oppositely disposed openings 30, 30' positioned medially of the flanges 28, 28. One end of the spring 26 which is mounted on the pin 24 bears against the inner surface of member 25 and the other end of spring 26 rests in notches 32 in the end of support 22, thereby maintaining member 25 normally projecting outwardly extending transversely across the path of the article being stitched, as shown in Figure 2. The outer end of article engaging member 25 has formed thereon a rounded V-shaped notched portion 33 which cooperates with arms 34, 34' mounted adjacent thereto and extending outwardly therefrom. The notched portion 33 and outwardly diverging arms 34, 34 form a thread guide means 35 which engages the chaining thread l9 when the bag I4 is no longer in con- 1 tact with the article engaging surface 21, whereby the chaining thread IB is forced against cu ting edge I! and is automatically severed.

In the modified forms of the invention shown in Figures 5 and 6, the supporting bracket 45 is detachably secured to the sewing machine It by clamps 4|. The outer end of bracket is provided with short L-shaped extensions 42, 42 on which is pivotally mounted the article engaging member 43. Member 43 has a flat article engaging surface 44 on the forward side thereof with rounded leading edge 45 and lateral flanges 45, 46 which straddle the L-shaped extensions 42, 42' of bracket 40. Means 41 is provided on lateral flanges 46 for pivotally mounting member 43 on extensions 42, 42. The outer end of member 43 is provided with lateral arms 48, 48 which in combination with the rounded V-shaped recess 49 cut in the end of member 43 comprise the thread guide means for forcing the chaining thread 19 against the cutting edge I'l. Disposed between the supporting bracket 45 and the article engaging member 43 is a spring 50 which may be of the coil or leaf type and normally maintains member 43 extending across the path of, the article being stitched. A reinforcing plate 5| is preferably employed to strengthen the lateral arms 48, 48'.

Many other modifications may be made in the manner of securing the supporting bracket to the sewing machine, in the form of the article engaging member, and in the form of the thread guide means. "For instance, it is not essential that the thread guide means and the article engaging member be in the same horizontal plane; The article engaging member may lie in a plane below the thread guide means and extend across the path of the article being stitchedat a point below the thread guide means so that the article engaging member will enga e the side of the bag well below the line of stitching. It is essential, however, that the article engaging member should be mounted so as to extend across the path of the article through the sewing machine, and the thread guide means should be disposed so as to bring the chaining thread into contact with the cutting edge when the article engaging member is no longer displaced by the article being stitched.

In the operation of the thread cutting attachment shown in Figures 1-4, filled bags H are continuously carried from the filling machines by mechanical conveyors through the sewing machine IB. The height of the machine I3 is so regulated that the upper edge of the filled bags I4 is engaged by the presser foot I2 and is moved rearwardly along a horizontal path while the sewing operation progresses to completion. When the advancing edge of the filled bags l4 passes the heel [2' of the presser foot. l2, it. engages the fiat surface 2'! of the article "engaging member 25 and forces the said member 25 to swing rear- Wardly against the tension of spring 26 away from the cutting edge 11 in the direction of the move ment of the article being stitched, as shown in Figure 1. As soon as the stitched bag [4 is conveyed away from the sewing machine ll along its horizontal path and the article engaging member 25 is no longer held in its retracted position by the bag, the member 25 will swing forwardly rapidly under the compulsion of the spring 26 and thread guide means 35 simultaneously engages the chaining thread [9 extending from the stitched bag l4 and forces the thread l9 against the cutting edge [1, as shown in Figure 2. The force with which the chaining thread l9 strikes the cutting edge I"! is sufficient to immediately sever the thread despite the absence of a cutting edge on the thread guide means 35. The article engaging member 25 remains in its forward position extending across the path of the article being stitched with the guide arms 34, 34 straddling the cutting edge I! until the next filled bag is conveyed through the sewing machine In and forces the member 25 to swing rearwardly out of the path of, the bag being stitched and away from the cutting edge [9. As soon as the stitched bag l4 leaves the sewing machine It], the member 25 swings forwardly again and the thread severing operation is repeated automatically.

The modified forms of the invention shown in Figures 5 and 6 operate in the same manner as the embodiment of the invention shown in Figures 1-4. The flat article engaging surface 44 of article engaging member 43 engages the filled bag being stitched, and the saidmember 43 swings rearwardly against the tension of spring 50 away from the cutting edge. As soon as the stitched bag is conveyed away from the sewing machine along its horizontal path and the article engaging member 43 is no longer held in its retracted position by the bag, the member 43 swings forwardly rapidly under the compulsion of spring 50. The thread guide means comprising lateral arms 48. 48 and the rounded V-shaped recess 49 engages the chaining thread extending from the stitched" bag and forces the thread against the cutting edge. The article engaging member 43 remains in its forward position extending across the path of the article being stitched until the next filled bag is conveyed through the sewing machine and forces the member 43 to swing rearwardly out of the path of the bag being stitched and away from the cutting edge.

The improved thread cutting attachment here in described is adapted for use on any type of sewing machine to sever the chaining loop immediately after completion of the sewing opera tion so that the tails will be as short as possible. And while particularly adapted for sewing machines in which successive articles to be stitched are fed through the machine in close succession, it is also adaptable to sewing machines which are stopped after the sewing of each article and functions in the usual manner by severing the tail of the thread close to the article and just after the last stitch is made upon the article.

Obviously many modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

1. A sewing machine attachment adapted to cooperate with a stationary cutting edge for severing the chaining thread between successively stitched articles comprising: a stationary supporting bracket having the outer end of said bracket disposed adjacent the heel of the sewing machine presser foot, a stationary cutting edge mounted on the work support opposite said end of the bracket, an article engaging member pivotally mounted on the said end of the supporting bracket and adapted to be yieldably displaced rearwardly away from the cutting edge and the presser foot by the article being stitched and having mounted at the rear thereof a thread guide means for forcing the chaining thread against the cutting edge when the article engaging member is no longer displaced rearwardly away from the fixed cutting edge, and yieldable means for maintaining the said article engaging member normally extending across the path of the stitched article through the machine but which allows the said member to be yieldably displaced from the cutting edge during the stitching operation when the said member is engaged by the article.

2. A sewing machine attachment adapted to cooperate with a stationary cutting edge for severing the chaining thread between successively stitched articles comprising: a stationary supporting bracket mounted on the sewing head of the machine and having the outer end of said supporting bracket adjacent the heel of the sewing machine presser foot and opposite a stationary cutting edge mounted on the work support of the machine, an article engaging member pivotally mounted on the said end of the supporting bracket and adapted to be yieldably displaced away from the cutting edge and the presser foot by the article being stitched and having mounted at the rear thereof a thread guide means having diverging arms for forcing the chaining thread against the fixed cutting edge when the article engaging member is no longer displaced rearwardly from the cutting edge by the said article, and yielding means mounted in the article engaging member for maintaining the said article engaging member normally extending across the path of the stitched article through the machine but which allows the said member to be yieldably displaced from the cutting edge during the stitching operation when the said member is engaged by the said article.

3. A sewing machine attachment adapted to cooperate with a stationary cutting edge for severing the chaining thread between successively stitched articles comprising: a stationary supporting bracket mounted on the sewing head of the machine and having the outer end of said supporting bracket disposed adjacent the heel of the presser foot and opposite a stationary cutting edge on the work support of the machine, an article engaging member pivotally mounted on the said end of the supporting bracket and adapted to be yieldably displaced rearwardly away from the cutting edge and the presser foot by the article during the stitching operation, said article engaging member having outwardly diverging arms extending rearwardly from the end of said member forming a guide means for forcing the chaining thread against the fixed cutting edge when the article engaging member is no longer yieldably displaced from the cutting edge, and yieldable means mounted in said article engaging member for maintaining the said article engaging member normally extending across the path of the stitched article through the machine but which allows the said member to be yieldably displaced outwardly from the cutting edge during the stitching operation when the said member is engaged by the said article.

4. A sewing machine attachment adapted to cooperate with a stationary cutting edge for severing the chaining thread between successively stitched articles comprising: a stationary supporting bracket mounted on the sewing head of the sewing machine and having the outer end of said supporting bracket disposed adjacent the heel of the presser foot and opposite a stationary cutting edge mounted on the work support of the sewing machine opposite the said end of the bracket, an article engaging member pivotally mounted on the said end of the supporting bracket and adapted to be yieldably displaced rearwardly away from the cutting edge and the presser foot by the article being stitched, said article engaging member having an elongated fiat article engaging surface with the end thereof having mounted thereon outwardly diverging arms which straddle the stationary cutting edge and form a guide means for forcing the chaining thread against the cutting edge when the article engaging member is no longer yieldably displaced away from the cutting edge, and spring means mounted in the said member for maintaining the said article engaging member normally extending transversely across the path of the stitched article through the machine and allowing said member to be yieldably displaced from the cutting edge during the stitching opera-,

tion when the said member is engaged by the said article.

NATHAN BATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,262,294 Merrifield Nov. 11, 1941 2,293,236 Anderson Aug. 18, 1942 2,426,026 Kehrer Aug. 19, 1947 

